Maximum 520STfm TOS version Etc

Upgrade or replace the ROM.
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rubber_jonnie
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Re: Maximum 520STfm TOS version Etc

Post by rubber_jonnie » Fri Aug 09, 2019 7:04 pm

PhilC wrote:
Fri Aug 09, 2019 2:32 pm
rubber_jonnie wrote:
Fri Aug 09, 2019 10:45 am
One word of warning when you are working around SR98, the aluminium heat sink is live when power is on!
Three guesses how I found that out :shock:
Pretty sure it was the same way I did!
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

tzok
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Re: Maximum 520STfm TOS version Etc

Post by tzok » Fri Aug 09, 2019 8:13 pm

AtariFox wrote:
Wed Aug 07, 2019 6:37 pm
It currently has a Mitsumi Elec PSU in it The big black capacitor with the big red warning on it is curved at the top, i dunno if that's by design, but there's no stress or bulge looking damage (include a picture).
It is kompletely normal, there is a plastic hemispherical cap ot top of this capacitor. It also fooled me once.

I've recapped one or two such PSU, and all capacitors were in great condition after testing them. Actually some had lower ESR and higher capacity than their brand new, modern Chinese equivalents.

AtariFox
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Re: Maximum 520STfm TOS version Etc

Post by AtariFox » Sat Aug 10, 2019 5:16 am

Thank you everyone for the information.
I will go ahead and sort out the parts i need to get everything ready in future.

It will be my first time recapping a PSU, But I am sure i'll be okay, I'll snag a pack of the dummy load things and get them set up. Should i snag a STFM Video recap just as a backup too?

Also. Should i put a blitter in the STFM? How would i go about that? I'm not entirely sure what that does though.

I am looking at getting the UBE video adapter though. But Is there a cable that lets you use the Sm124 monitor on a pc at 640x400?

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Re: Maximum 520STfm TOS version Etc

Post by rubber_jonnie » Sat Aug 10, 2019 11:31 am

Sounds like you have a plan, so here's some advice on the process, based on my experiences with SR98s.

1. Take a photo beforehand that shows the capacitor polarity so that you can make sure the new caps are correctly aligned before you power on. The polarity is marked, but it's worthwhile being 100% certain before adding power.

2. I find fluxed desolder wick is much easier to use than a solder sucker. It's inexpensive and you can see the solder being removed visually as you go. It is also much more controllable than a solder sucker.

3. You will need to drill through the PCB to enlarge the holes for the new bridge rectifier. Do this from the bottom and take care when doing so, as it is possible to snag the tracks with the drill bit and damage them. It isn't the end of the world if this does happen, but best to avoid it in the first place. You will almost certainly push the tracks off if you drill through from the top.

4. Use the dummy load resistors to help set the 5v output. Connect both resistors (5v side and 12v side) power on and check the 5v side. Adjust the pot near to R201 & R202 that you replaced earlier until the voltage is correct. Be aware that the resistors get very hot, and once again, when adjusting the pot, stay well clear of the aluminium heatsink to avoid possible electric shocks.

See here for more detail: http://www.exxoshost.co.uk/atari/last/p ... x.htm#SR98

The main piece of advice for your first one is to take your time. Let us know how you get on.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

AtariFox
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Re: Maximum 520STfm TOS version Etc

Post by AtariFox » Sat Aug 10, 2019 12:39 pm

rubber_jonnie wrote:
Sat Aug 10, 2019 11:31 am
See here for more detail: http://www.exxoshost.co.uk/atari/last/p ... x.htm#SR98

The main piece of advice for your first one is to take your time. Let us know how you get on.
I'll let everyone know how i get on, Not sure how soon i'll be able to do it.

What size drill bit am i looking for exactly?

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Re: Maximum 520STfm TOS version Etc

Post by rubber_jonnie » Sat Aug 10, 2019 12:51 pm

It's 1mm, see the link I shared earlier.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

AtariFox
Posts: 36
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Re: Maximum 520STfm TOS version Etc

Post by AtariFox » Tue Aug 13, 2019 10:36 am

Thanks for the info on the drill bit!

I looked in the Atari today under the shielding, and i have a 2 rom version of the STFM.

I however cannot find any of the two rom versions of 1.04. I don't really know where to look. If i even have 1.04 already installed lol

I am not capable of any sort of heavy motherboard modification.

Heres a picture of the roms if you can help determine the chips i have and what i need.
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PhilC
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Re: Maximum 520STfm TOS version Etc

Post by PhilC » Tue Aug 13, 2019 10:45 am

To upgrade to 1.04 the simplest way will be to get one of exxos's rom boards and roms, you can have switchable tos 1.02 and 1.04
If it ain't broke, test it to Destruction.

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Re: Maximum 520STfm TOS version Etc

Post by rubber_jonnie » Tue Aug 13, 2019 10:55 am

PhilC wrote:
Tue Aug 13, 2019 10:45 am
To upgrade to 1.04 the simplest way will be to get one of exxos's rom boards and roms, you can have switchable tos 1.02 and 1.04
I'd agree with this, plus it will mean you can simply plug in the dual ROM kit where the chips once were.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

AtariFox
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Joined: Wed Aug 07, 2019 6:13 pm

Re: Maximum 520STfm TOS version Etc

Post by AtariFox » Tue Aug 13, 2019 10:59 am

Does that work on the D1 revision board? or DI , I cant tell if it's a one or an i

I dont want to do any case modifications or otherwise.

So I'd need the STFM KIT DUAL TOS & UBE BETA (NO ROM) [0131] and a TOS104 / TOS102 ROM ENGLISH [0042] from exxos's store?
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